Currently, there are many ways of providing access to properties that are for sale or rent. Access is provided so that prospective buyers/renters and some contractors are able to inspect the property to understand if the property meets their needs/requirements, especially when the buyers/renters will make such property their home.
Real estate agents typically require access to properties so that they can show their clients what is being offered. In many scenarios, the real estate agent is needed as many properties being shown are occupied requiring scheduling and a trusted/bonded person to escort the prospective buyers to protect the property and contents of the property, although some properties are vacant and there are no contents that need protection.
In general, most properties are typically protected by a locking system to prevent burglary, vandalism, and squatting (living in a property that is not owned by the person living in such). Many locking systems involve a door that has a lock, either a key-entry lock or a newer, electronic lock.
A long time ago, a listing real estate agent had access to all the properties that he or she listed by a large supply of keys, one key for each property. When a client wanted to see a property, the agent finds the key for that property and goes to the property with the client. This method may work for a very small town, but as larger towns and cities grew, it became difficult to manage so many keys.
To reduce the need for a huge amount of keys while providing access to properties by agents and buyers, lockboxes were made. Initially, lockboxes were mechanical having a padlock-like arm that secured the lockbox to the property, usually around a door handle, and a cavity for holding a property key that could only be accessed by a master key or a combination known only to real estate agents that were approved to access the property. Upon arriving at the property, the agent would provide the access key that would open the cavity and expose the property key that the agent then uses to open the door to the property.
As the lockboxes evolved, electronic versions were introduced that used wireless key fobs to access the property key, then as smart-phones became more ubiquitous, the lockboxes were designed to provide access when an application running on the smart-phone sent certain cryptographic signals to the lockbox, for example, using Bluetooth technology. Still, the real estate agents are required since there is still a need to make sure nothing is removed from the property and nothing is damaged.
In some real estate scenarios, the property is vacant and, hence, it is not as much of a concern that a real estate agent be present while the prospective buyer visits the property. For example, a qualified buyer is able to walk through a vacant condominium without the need for an agent to follow them through every room. There are many situations in which there are many such properties in a relatively close geographical area, such as when a tract of houses are built or a new condominium is built. There are often tens or hundreds of homes or apartments that lay vacant for viewing by prospective buyers. Today, one or more agents is/are situated at such locations during business hours to escort prospective buyers through available properties.
What is needed is a system that will provide access to properties by individual buyers that are prequalified for access.